I have a decently severe anxiety disorder, accompanied by tremors, increased heart rate, sweats, chills, etc... I have a prescription to xanax to help with this, but when I'm really faced with a situation that I need to be able to pragmatically deal with my anxiety, it doesn't really help.

I've looked up the dosage to xanax, and I've read that in studies the most effective dose for dealing with high anxiety patients was 4 mg administered over the course of a 24 period. My question is what dosage should I take to avoid becoming incredibly frantic at an important presentation that I have coming up, a presentation in which I need to be calm and collected at. I'm not sure if body size has anything to do with it, but I'm around 6 ft. and 220 lbs.

4 mg/d of xanax is a pretty hefty dose, though it can be warranted. The major liability of xanax for people with anxiety disorders is that it wears off quickly, causing anxiety as it wears off potentially, and necessitating multiple daily doses. In addition, patients can have a severe withdrawal reaction if they lower their xanax dose quickly, and it can be hard to taper. Often, patients with anxiety respond better to the medication clonazepam, as it lasts much longer, and thus works more "smoothly" & is usually dosed twice a day.

For a once-in-a-while dose of xanax for a presentation, a patient might be prescribed from .25-1mg; a higher dose could be warranted with much caution and only if lower amounts were tried first.

Have you considered getting some cognitive-behavioral training or other appropriate psychotherapy for your anxiety disorder? Often, the medications alone simply are not enough.